Remove unused parent_hash in OverlayedChanges::into_storage_changes (#11011)

Ref https://github.com/paritytech/substrate/pull/10922#issuecomment-1064258443

CC @cheme

substrate/utils/frame/try-runtime/cli/src/commands/follow_chain.rs

@@ -150,7 +150,6 @@ where
 		let storage_changes = changes
 			.drain_storage_changes(
 				&state_ext.backend,
-				Default::default(),
 				&mut Default::default(),
 				// Note that in case a block contains a runtime upgrade,
 				// state version could potentially be incorrect here,